This invention relates to a tape drive for use in a linear tape storage system represented by DLT (Digital Linear Tape) or LTO (Linear Tape Open) and, in particular, to an interpose lever for holding a tape cartridge (or a tape cassette) in a tape drive.
A linear tape storage system of the type has been developed as a backup for a computer system. A variety of linear tape storage systems have heretofore been proposed. For example, a digital linear tape drive as the DLT is disclosed in U.S. Pat. No. 5,862,014.
The digital linear tape drive is adapted to receive a tape cartridge having a single supply reel. The digital linear tape drive includes a take-up reel in the interior thereof. When the tape cartridge is received in the tape drive, a magnetic tape is pulled out from the tape cartridge to be taken up by the take-up reel through a head guide assembly. The head guide assembly serves to guide to a magnetic head the magnetic tape pulled out from the tape cartridge. The magnetic head exchanges information to and from the magnetic head.
Typically, a tape drive comprises a generally rectangular housing having a common base as disclosed in U.S. Pat. No. 5,793,574 for example. The base has two spindle motors. The first spindle motor has a permanently mounted spool as a take-up reel permanently mounted to the base and dimensioned to accept a magnetic tape streaming at a relatively high speed. The second spindle motor is adapted to receive a removable tape cartridge.
The tape cartridge is manually or automatically inserted into the drive via a slot formed on a housing of the drive. When the tape cartridge is inserted into the slot, the cartridge is engaged with the second spindle motor. Prior to rotation of the first and the second spindle motors, the tape cartridge is connected to the permanently mounted spool by means of a mechanical buckling mechanism. A number of guide rollers are positioned between the tape cartridge and the permanently mounted spool and guide the magnetic tape as it streams at a relatively high speed back and forth between the tape cartridge and the permanently mounted spool.
The tape drive further comprises a head assembly. The head assembly is positioned between the spool and the tape cartridge along a tape path defined by a plurality of rollers. During operation of the tape drive, the magnetic tape streams along the tape path between the spool and the tape cartridge, coming into close proximity to the head assembly while streaming. An example of the head assembly is disclosed in U.S. Pat. No. 5,793,574 mentioned above. Japanese Unexamined Patent Publication No. 2000-149491 (JP 2000-149491 A) discloses an example of the tape cartridge to be received in the digital linear tape drive.
After the tape cartridge is inserted into the tape drive, it is necessary to hold the tape cartridge at a proper position. For this purpose, the tape drive is provided with an interpose lever for holding the tape cartridge. After completion of information exchange upon the magnetic tape, the magnetic tape is rewound into the tape cartridge. Thereafter, by an eject mechanism operated by an operator, the tape cartridge is ejected from the tape drive. In order to eject the tape cartridge, it is necessary to release holding of the tape cartridge by the interpose lever.
In view of the above, the interpose lever comprises a movable base having a protrusion to be engaged with a recess formed on the tape cartridge, a release arm for releasing engagement between the protrusion and the recess, and a shaft as a separate component to which the release arm is attached to be rotatable with respect to the base.
However, the above-mentioned tape drive requires the shaft to be provided as another component separate from the base and the release arm. In addition, an E ring constituting a thrust bearing is also required. Thus, the number of components of the interpose lever is increased so that an assembling efficiency is decreased. As a consequence, it is difficult to reduce the cost of the interpose lever.
It is therefore an object of this invention to provide an interpose lever which can be reduced in number of components.
It is another object of this invention to provide an interpose lever which can be reduced in number of assembling steps.
It is still another object of this invention to provide an interpose lever which can reduced in cost.
It is yet another object of this invention to provide an inexpensive tape drive which can be reduced in number of components and in number of steps.
According to this invention, there is provided an interpose lever for holding a removable tape cartridge in a tape drive. The interpose lever comprises a movable base having a protrusion to be engaged with a recess formed on the tape cartridge to inhibit the tape cartridge from being released, a release arm rotatably attached to the base for releasing engagement between the protrusion and the recess, urging means for urging the release arm in a predetermined rotating direction, and a shaft formed integral with the base to serve as a rotation center member for the release arm.
According to this invention, there is also provided a tape drive which comprises a housing having a slot for receiving a tape cartridge containing a tape, an interpose lever as mentioned above, the interpose lever being assembled to the housing, and a tape driving mechanism assembled to the housing for moving the tape in the tape cartridge loaded in the slot.